Shishi-odoshi (鹿威し) (literally, "deer-frightening" or "boar-frightening"), in a wide sense, refers to Japanese devices made to frighten away animals that pose a threat to agriculture, including kakashi (scarecrows), naruko (clappers) and sōzu.
A sōzu is a type of water fountain used in Japanese gardens.
It consists of a segmented tube, usually of bamboo, pivoted to one side of its balance point.
The heavier end then falls back against the rock, making a sharp sound, and the cycle is repeated.
[1] These fountains were originally intended to startle any herbivores, such as deer or boars, which might be grazing on the plants in the garden, but shishi-odoshi are now a part of the visual and aural design of gardens, and are used primarily for their aesthetic value.